Sorting organisms into categories seems pretty simple at first, but look a little closer and things get weird. Hosted by: Michael Aranda ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Dooblydoo thanks go to the following Patreon supporters—we couldn't make SciShow without them! Shout out to Kevin Bealer, Mark Terrio-Cameron, KatieMarie Magnone, Patrick Merrithew, Charles Southerland, Fatima Iqbal, Benny, Kyle Anderson, Tim Curwick, Scott Satovsky Jr, Philippe von Bergen, Bella Nash, Bryce Daifuku, Chris Peters, Patrick D. Ashmore, Charles George, Bader AlGhamdi ---------- Looking for SciShow elsewhere on the internet? Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Tumblr: http://scishow.tumblr.com/ Instagram: http://instagram.com/thescishow ---------- Sources: http://www.nature.com/scitable/topicpage/why-should-we-care-about-species-4277923 http://eol.org/info/468 http://evolution.berkeley.edu/evolibrary/article/evo_41 http://science.kennesaw.edu/~rmatson/Biol%203380/3380species.html http://evolution.berkeley.edu/evolibrary/article/side_0_0/biospecies_01 http://www.pbs.org/wgbh/evolution/library/05/2/l_052_05.html http://www.askabiologist.org.uk/from_the_lab/species-concepts http://science.sciencemag.org/content/354/6314/817 http://science.sciencemag.org/content/354/6314/818 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0068267 Images: https://commons.wikimedia.org/wiki/File:Ernst_Mayr_PLoS.jpg https://commons.wikimedia.org/wiki/File:Empidonax_alnorum_CT2.jpg https://commons.wikimedia.org/wiki/File:Southwestern_Willow_Flycatcher.jpg https://commons.wikimedia.org/wiki/File:Single-cell-time-lapse-analysis-of-depletion-of-the-universally-conserved-essential-protein-YgjD-1471-2180-11-118-S11.ogv https://commons.wikimedia.org/wiki/File:Araberganz.jpg https://commons.wikimedia.org/wiki/File:Donkey_1_arp_750px.jpg https://commons.wikimedia.org/wiki/File:Juancito.jpg https://commons.wikimedia.org/wiki/File:Ensatina_eschscholtzii_ring_species.jpg Thumbnail Image: Repeating Patterns of Mimicry. Meyer A, PLoS Biology, Vol. 4/10/2006, e341 http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040341